Remove trailing whitespace.

Also adds a presubmit to prevent adding trailing whitespace to source
code in the future.

Change-Id: I41a4df81487f6f00aa19b188f0cac6a3377efde6
Reviewed-on: https://skia-review.googlesource.com/57380
Reviewed-by: Ravi Mistry <rmistry@google.com>
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
diff --git a/tests/PathOpsTigerTest.cpp b/tests/PathOpsTigerTest.cpp
index db1b27d..e8b21af 100644
--- a/tests/PathOpsTigerTest.cpp
+++ b/tests/PathOpsTigerTest.cpp
@@ -252,7 +252,7 @@
                     testlines |= 1LL << bit;
                 }
                 *testRunner.fRunnables.append() =
-                        new PathOpsThreadedRunnable(&testTiger, 
+                        new PathOpsThreadedRunnable(&testTiger,
                                                     (int) (unsigned) (testlines & 0xFFFFFFFF),
                                                     (int) (unsigned) (testlines >> 32),
                                                     ab, 0, &testRunner);